Forty-four surface sediments from Sanya offshore area are analyzed for assessing heavy metals (Cu, Pb, Zn, Cr, Cd, Hg, and As) pollution. High metal values except for As are located in the southern areas which have fine-particle presence. However, high values of the metal As appear at a depth of 15-30 m in the Yazhou Bay. As and Pb show moderate contamination, and other metals show low contamination. The metals (except for As) are confirmed not to be enriched to slightly enriched, which are controlled by the grain size and mainly derived of the natural weathering products. The moderately severe to severe enrichment of As occurs in the Yazhou Bay and the nearshore area of the Sanya Bay. The reason is due in part to the excessive use of agricultural fertilizers. Further, it is also likely to be related to the high background value of As in the sea area.Contamination status of traditional and emerging persistent toxic substances (PTSs) in sediments and their major sources were investigated in Ulsan Bay, Korea. A total of 47 PTSs, including 15 traditional PAHs, ten styrene oligomers (SOs), six alkylphenols (APs), and 16 emerging PAHs (E-PAHs) were analyzed. Concentrations of traditional PAHs, SOs, and APs ranged from 35 to 1300 ng g-1 dry weight (dw), 30 to 3800 ng g-1 dw, and 30 to 430 ng g-1 dw, respectively. For the last 20 years, PTSs contamination in the bay area has been improved. However, 12 E-PAHs were widely detected in sediments, with a maximum of 240 ng g-1 dw (for benzo[e]pyrene) at the creek site. https://www.selleckchem.com/products/MK-1775.html These E-PAHs seemed to originate from surrounding activities, such as biomass combustion, mobile sources, and diesel combustion. Due to environmental concerns for E-PAHs, further research on the potential toxicity, distribution, and behavior of these compounds should be implemented.The lagoons of seven French Polynesia and Cook Islands pearl farming atolls (Raroia, Takume, Mopelia, Takapoto, Ahe, Takaroa and Manihiki) were surveyed using multibeam and mono-beam sounders. From the detailed bathymetry, morphometric variables (average and maximum depth, frequency-area of depth, lagoon area and volume) are computed and compared. Remarkable geomorphological structures highlighted by bathymetric variations include deep reticulated structures and pinnacles. The seven atolls appear very different in abundance, size and density of these entities. Considering them as markers of the geological, sedimentological and eustatic processes that shape atoll lagoons, they are discussed in the context of the general theory of atoll lagoon formations involving karstic dissolution during Pleistocene or earlier low sea-level stands. In terms of pearl farming management, accurate bathymetric maps help pearl oyster wild stock assessment, development of circulation and biogeochemical models, better lagoon zoning and strategy to remove pearl farming derelict gears.To evaluate the surgical technique and accuracy of S2 alar-iliac (SAI) screw placement using intraoperative O-arm-based 3-dimensional navigation (O-arm).
This study involved 60 patients who underwent SAI screw placement using the O-arm system between September 2013 and September 2019. These surgeries were performed by 5 different surgeons. For O-arm-based SAI screw insertion, a reference frame was attached to the spinous process of the lower lumbar spine (usually L4) so as not to interfere with SAI screw insertion and to facilitate simultaneous L5-S posterior interbody fusion with navigation. The navigated probe, iliac tap, and screwdriver were used for SAI screw insertion. Screw placement accuracy and screw length were assessed using postoperative computed tomography. Perioperative complications were also evaluated.
Mean age at surgery was 68.1 (range, 30-83) years. In total, 120 screws were inserted. Rate of accurate screw placement was 98.3% (118/120 screws). The 2 misplaced screws breached the anterior cortex of the sacrum. Mean screw length was 85.6 (range, 70-90) mm. There were no significant neurovascular or visceral complications perioperatively.
SAI screw placement can be safely performed using the intraoperative O-arm system and our surgical technique.
SAI screw placement can be safely performed using the intraoperative O-arm system and our surgical technique.Lumbar burst fractures (complete or incomplete) of L5 have a low incidence, accounting for 1.2% of all spinal burst fractures. Treatment for these fractures remains controversial. Decompression of neural elements and stabilization of the spine to preserve lordosis and avoid kyphotic deformity are recommended when a patient has a neurological deficit and an unstable fracture. Otherwise, the fracture could be managed conservatively.
We report a detailed step-by-step unilateral biportal endoscopy technique used in a patient with an L5 incomplete burst fracture and neurological deficit.
The patient had an acceptable immediate postoperative course; lower back pain and radicular symptoms improved significantly after surgery.
Our unilateral biportal endoscopy technique for L5 incomplete burst fractures offers the capability to perform enough decompression of neural elements and assist other procedure-related maneuvers under direct endoscopic visualization. This technique could be considered another minimally invasive spine surgery option for treating selected patients with L5 incomplete burst fractures.
Our unilateral biportal endoscopy technique for L5 incomplete burst fractures offers the capability to perform enough decompression of neural elements and assist other procedure-related maneuvers under direct endoscopic visualization. This technique could be considered another minimally invasive spine surgery option for treating selected patients with L5 incomplete burst fractures.Deep brain stimulation is an effective treatment for severe tremor in essential tremor and Parkinson disease (PD). However, progressive loss of the beneficial effects of deep brain stimulation may occur due to several factors.
We assessed the effects of different temporal patterns of cycling stimulation in the posterior subthalamic area, subthalamic nucleus, and the ventral intermediate nucleus of the thalamus in 3 PD patients with early decline of tremor suppression associated with severe tremor rebound.
Certain temporal patterns of cycling (10 seconds on/1 second off or 30 seconds on/5 seconds off, soft start off) were useful for treating tremor habituation and rebound and showed long-term tremor suppression. Cycling stimulation may prevent tremor habituation in PD patients with severe tremor rebound.
Certain temporal patterns of cycling (10 seconds on/1 second off or 30 seconds on/5 seconds off, soft start off) were useful for treating tremor habituation and rebound and showed long-term tremor suppression.